Cover lock mechanism

ABSTRACT

A cover of a housing for containing various control devices mounted under the floor of a vehicle can be opened by itself due to vibration during traveling of the vehicle, in the case of forgetting to lock the cover or improper locking, resulting in possible danger. A latch is held by a leaf spring that is mounted on the backside of the cover and the latch is biased from a center of an opening of the housing toward a periphery thereof. When the cover is opened, a hook formed at the latch is hooked on a periphery of the opening by bias force from the leaf spring, thus preventing the cover from being opened further. By inserting a finger through a slightly open gap to release the hook, the cover can be opened easily.

TECHNICAL FIELD

The present invention relates to a lock mechanism of a cover mounted viaa hinge onto a housing body that contains, e.g., electronic devicestherein.

BACKGROUND ART

Various electronic devices or pneumatic/hydraulic control devices aremounted onto moving bodies such as trains or automobiles. These variouscontrol devices may be mounted in an internal part of the automobile, ormay be mounted under floor or on roof. Many of these varieties ofcontrol devices are extremely important devices for safety reasons of amoving body. Accordingly, wherever these control devices are located, itis necessary to put them in an internal part of a housing provided witha cover in order to protect the mentioned control devices from wind,rain, snow, or dust. A variety of housings provided with covers intendedto meet such requirements have been proposed.

A housing provided with such a cover generally adopts a construction offully closing a cover 2 by locking the cover 2 having been closed with apawl 5 a equipped with a handle 5 as shown, for example, in an externalappearance view of FIG. 9 and a cross sectional view of FIG. 10.

This construction is such that the cover 2 is mounted onto a hinge 3that is attached to a housing body 1, whereby the cover makes an opening10 of the housing body open and closed with the hinge 3 acting as afulcrum, and such that a pawl 5 a is turned along with the handle 5being turned when closing the cover 2, and is hooked on an edge of theopening of the housing 1.

However, with such a construction, there is a disadvantage such that thecover 2 may be opened while the vehicle is traveling, for example, inthe case where a maintenance worker forgets to lock or it is in thestate of improper locking after the maintenance inspection of devices inan internal part of the housing. With reference to FIG. 10, the hinge 3is located on the upper side (this is hereinafter referred to asupper-hinged type for reasons of description), and the cover 2 is closedby itself under its weight and can be opened only by lifting it up bymanpower in the case of opening. In the case where the hinge 3 islocated on the lower side (this is referred to as lower-hinged type, notshown) and the cover 2 is opened downward, the cover may be openedsuddenly under weight of the cover at the moment when the pawl 5 a isreleased, resulting in a further problem of being dangerous in the caseof a heavy cover 2. As means of solution to such problems, a devicedisclosed in Patent Document 1 was proposed.

The device disclosed in Patent Document 1 is constructed such that a rodstay (20) that is attached to a door is hooked on a pin (22) that isformed on the housing side under weight of the stay itself when a door(12) is opened, whereby the door (12) is held at a predetermined angle.

However, the construction disclosed in Patent Document 1 cannot beapplied to the one of upper-hinged type or left-hand/right-hand type(because the stay cannot be hooked under its own weight).

Patent Document 1: the Japanese Patent Publication (unexamined) No.173513/1994 “Stay”, FIG. 1

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

A problem exists in that the cover 2 may be opened while the vehicle istraveling in the case of forgetting to lock, or being in the state ofimproper locking after the maintenance inspection of devices in aninternal part of the housing. Furthermore, another one is proposed inthat a rod stay that is attached to a door is hooked on a pin that isformed on the housing side under weight of the stay itself when the dooris opened, whereby the door is held at a predetermined angle. However, afurther problem exits in that this construction cannot be applied to theone of upper-hinged type or left-hand/right-hand type.

The present invention was made to solve each of the conventionalproblems as described above at the same time, and has an object ofproviding a lock mechanism that can be employed without regard to whichdirection a cover is opened in, and that prevents the cover from beingopened at not less than an arbitrary angle even in the case where anoperator fails to do lock operation.

A cover lock mechanism according to the present invention is mountedonto a cover that is attached rotatably with a hinge, which is fixed toa housing mounted on, e.g., a vehicle, and that makes an opening of thishousing open and closed; and prevents the cover from being fully openedaccidentally. This cover lock mechanism comprises a latch that is heldwhile being biased from a center of the mentioned opening toward aperiphery of the mentioned opening by means of a leaf spring mountedonto a side of the cover being in contact with the mentioned opening,that can move along a direction of connecting an arbitrary point on aperiphery of the mentioned opening and a center of mentioned opening,and that includes a hook, which is hooked on an arbitrary point of theperiphery of the mentioned opening.

As a result of this construction, the cover lock mechanism according tothe invention makes it possible to prevent a cover from being opened atnot less than an arbitrary angle even in the case where an operatorfails to do lock operation, and furthermore this cover lock mechanismcan be used regardless of which direction the cover is opened in.

EFFECT OF THE INVENTION

According to the lock mechanism of the invention, advantages can beobtained by an extremely simple construction such that the lockmechanism is held by means of a leaf spring that is mounted on thebackside of a cover even if the cover is opened by itself due to anyvibration during traveling the vehicle at the time of forgetting to lockthe cover or being in the state of insufficient locking; as well as thata hook formed at a latch, which is biased from a center of an opening ofthe housing toward a periphery thereof, is hooked on the periphery ofthe opening due to bias force provided by the leaf spring, thuspreventing the cover from being further opened and preventing theinternal devices from being damaged.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1

A cover lock mechanism according to a first preferred embodiment of thepresent invention is hereinafter described referring to the drawings.FIG. 1 is a cross sectional view showing a housing structure of, e.g., acontrol device to which cover lock mechanism according to the inventionis applied. FIG. 2 is a perspective view of the backside of a cover 2taken from inside of a hosing 1 in order to facilitate furtherunderstanding of the structure. FIG. 3 is a partially detailed view forexplaining a latch of FIG. 1. FIG. 4 are explanatory views of operationat the time of closing the cover of FIG. 4. FIGS. 5 and 6 areexplanatory views at the time of opening it.

The cover lock mechanism of FIG. 1 can be used in any box structure oncondition that the box structure includes a door-type cover 2 that isopened and closed with respect to the housing 1 regardless of whichdirection the cover 2 is opened and closed in, and further, any devicesuch as control device, electronic device, or storage cabinet of partsor documents can be contained in an internal part of the foregoing boxstructure. In the cover lock mechanism of FIG. 1, the housing body 1 andthe cover 2 are connected so that a hinge 3 can be rotated. Although anexample in which the hinge 3 is located on the upper side is describedin this first embodiment, the hinge 3 may be positioned on the upper orlower side, or on the right-hand or left-hand side with respect to thecover 2. The cover 2 makes an opening 10 of the housing body 1 open orclosed with the hinge 3 acting as a fulcrum.

Periphery of the cover 2 is folded toward the side of the housing 1, andthis folded periphery is pressed to a packing P that is located on theinside of a packing gland 1 a formed at the peripheral portion of anopening 10 when the cover 2 is closed, thereby achieving improvement inwaterproof. The structure of a latch 4 of FIG. 2 is described with apartially detailed view of FIG. 3. An L-shaped leaf spring 4 b is weldedto the inner face of the cover 2. A latch 4 of steel plate is attachedby welding 4 z to the tip portion of the leaf spring 4 b, and moves upand down due to elastic deformation of the leaf spring 4 b. In thisregard, a further description is made as to what is referred to as “upand down” herein. An example in which the latch 4 is attached to thelower side of the cover 2 is described in FIG. 1, so that movingdirection of the latch 4 is up and down. However, for example, in thecase where the hinge 3 is located on the left-hand side of the cover 2and the cover is opened to the left, the latch 4 moves to the right orleft side. That is, generally speaking, the latch 4 moves in a directionof connecting the center of the cover 2 and a point on a periphery ofthe opening 10 to which the latch 4 is attached. There is provided arun-off 4 w that is cut obliquely at the rear end of the latch 4 so asto prevent the rear end of the latch 4 from being hit against the coverresulting in occurrence of a trouble when the latch 4 moves due todeformation of the leaf spring 4 b. The latch 4 includes an oblique part4 x that is molded in a beveled manner at the tip portion, and a hook 4Yin the vicinity of the lower end of the oblique part 4 x. In addition, alength (indicated by L) from the tip of the leaf spring 4 b to the hook4Y is a length obtained by further adding about 3 cm to 7 cm to theaddition of a height of the packing gland 1 a and a height of the foldedpart at the periphery of the cover 2.

Now, operation of the latch 4 according to the first embodiment isdescribed.

First, the operation in the case of closing is described with referenceto FIGS. 4(a) to (c).

FIG. 4 (a): The cover 2 is pressed in a direction of closing.

FIG. 4(b): The oblique part 4X of the latch 4 is interfered with thepacking gland 1 a of the housing 1 or with the edge of the opening 10.

FIG. 4(c): The oblique part 4X is pushed upward against the reactionforce of the leaf spring to slide on the upper face of the packing gland1 a, and the latch 4 that is held with the leaf spring 4 b is insertedin an internal part of the housing.

Then, a lock, not shown, is put on and the cover 2 is secured.

Next, the case where the lock 5 of the cover 2 is released (or isreleased by intent) and the cover 2 is opened is described withreference to FIGS. 5 and 6.

FIG. 5: When the cover 2 begins to open, the latch 4 is hooked on theedge of the opening 10 of the housing 1, and the latch 4 is opened justto an extent of a length of the latch 4. Which angle the cover 2 ishooked at is determined depending on a length (L) of the latch 4.

FIG. 6: To open the cover further, a finger is inserted through a gapwith the cover 2 slightly opened, and a lower face of the latch 4 ispushed up. Then, the hook 4Y is released from the edge of the opening10, and the cover 2 is opened unrestrainedly.

Embodiment 2

Although there is provided a latch 4 only at one point of the cover 2 inthe drawings according to the first embodiment, it is preferable to belocated at two points of the cover 2 at the time of the cover 2 of alarge width. To open the cover 2, respective latches 4 are pushed up atthe same time with fingers of the right and left hands, thereby enablingto open it.

Further, in the drawings according to the first embodiment, the latch 4is located on the side of the cover 2 opposite to the side on which thehinge 3 is mounted. However, a latch 4 is not always necessary to belocated on this side. For example, it is preferable that the latch 4 islocated on the side adjacent to the side on which the hinge is mounted.Note, however, that when a position of the latch 4 being attached is toonear to the position of the hinge 3, a rotational movement at the timeof opening the cover 2 may act on the latch 4, thus making it possiblethat anchoring the latch 4 is operated undesirably. Accordingly, thelatch 4 is preferably mounted apart from the hinge 3.

Embodiment 3

In the case of employing the latch 4 of FIG. 3, while the latch being inthe state of FIG. 5, the cover 2 is opened or closed to the extent of alength L up to the hook 4Y of the latch 4 and is rattled by the movementof a vehicle, resulting in a danger of fingers being caught.

To prevent this, there is formed a notch 4R in front of the hook 4Y asshown in FIG. 6. A width of the notch 4R is slightly larger than a platethickness at the opening 10 of the housing 1, and depth of the notch 4Ris approximately a few millimeters.

In the case where the notch 4R is formed, in the state of FIG. 6according to the first embodiment, the edge of the opening 10 is lockedinto the notch 4R, whereby the cover 2 is nearly secured, resulting inno fear of fingers being caught. As a matter of course, the cover issecured with the notch 4R at the time of closing the cover 2, so thatthe cover has to be closed by lifting it up with fingers.

Embodiment 4

The latch 4 is made of a steel plate, and is welded to the leaf spring 4b according to the first to third embodiments, so that it takes muchman-hour to manufacture it. Therefore, it is preferable to employ aplate latch 40 made of only a leaf spring as indicated by referencenumber 40 in FIG. 8. In this case, press-embossing a part of the leafspring forms a part that corresponds to the notch 4R according to thethird embodiment. A part that corresponds to the oblique part can beformed only by folding a leaf spring at a proper angle.

INDUSTRIAL APPLICABILITY

The cover lock mechanism according to the present invention is notlimited to the one that is mounted on a moving body, but can be appliedto other fixed facilities. Furthermore, the cover lock mechanism is notnecessarily limited to a cover of the housing, but can be utilized alsoin, for example, doors of an opening/closing hatch of wiring inspectionaccess hole on the ceiling.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross sectional view of a cover lock mechanism according toa first preferred embodiment of the present invention.

FIG. 2 is an explanatory view of the backside of a cover of FIG. 1.

FIG. 3 is a partially detailed view for explaining a latch of FIG. 1.

FIG. 4 are explanatory views of operations at the time of closing thecover of FIG. 1.

FIG. 5 is an explanatory view of operation at the time of opening thecover.

FIG. 6 is an explanatory view of a method of releasing the latch for thepurpose of opening the cover.

FIG. 7 is a partially detailed view of a latch of a cover lock mechanismaccording to a third embodiment.

FIG. 8 is a partially detailed view of a latch of a cover lock mechanismaccording to a fourth embodiment.

FIG. 9 is an explanatory view of external appearance of a cover.

FIG. 10 is a cross sectional view of FIG. 9.

DESCRIPTION OF REFERENCE NUMERALS

1: housing, 1 a: packing gland, 2: cover, 3: hinge, 4: latch, 4 a: leafspring, 4R: notch, 4W: run-off, 4X: oblique part, 4Y: hook, 4Z: welding,5 a: pawl, 10: opening, 40: plate latch, 41: notch, P: packing

1. A cover lock mechanism comprising: a housing; a cover that is mountedrotatably with a hinge attached to said housing, and that forms anopening which causes said housing to be opened or closed; a latch thatis held by means of a leaf spring mounted onto a side of said coveradjacent to said opening, and that is biased from inside of said openingtoward a periphery thereof, and a hook that is formed on said latch, andthat is hooked on an arbitrary point of the periphery of said opening tohold said cover to be in a state of being slightly opened when saidcover is slightly opened forming a gap that allows fingers to beinserted.
 2. The cover lock mechanism according to claim 1, wherein saidcover comprises two latches.
 3. The cover lock mechanism according toclaim 1, wherein said latch comprises a notch that is formed betweensaid hook and said cover, and holds the cover.
 4. The cover lockmechanism according to claim 1, wherein said latch is manufactured byshaping a leaf spring that is mounted onto the side of said coveradjacent to said opening.